Free Edge Supported Mitral Valve

ABSTRACT

A transcatheter stent-valve having replacement leaflets that are attached along their free edges. The stent-valve frame has supports that extend distally of the replacement leaflets to two fastening sites. The replacement leaflets are attached along a leaflet base forming a linear attachment to the stent-valve frame. The free edges of the leaflets have cords attached; the cords attach the free edges of the leaflets to the fastening sites located on the supports. The stent-valve can be a single component stent-valve or it can be a second component of a dual component stent-valve.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application makes reference to and thereby incorporates allinformation found in the provisional patent applications No. 62/494,540entitled Free Edge Supported Mitral Valve Leaflets filed 12 Aug. 2016,62/497,713 entitled Free Edge Supported Mitral Polymer Leaflets filed 29Nov. 2016, all by William J. Drasler, et. al., and Nonprovisional patentapplication Ser. No. 15/457,626 entitled Two Component Mitral Valvefiled 13 Mar. 2017, by William J. Drasler, et. al.

BACKGROUND OF THE INVENTION

Transcatheter mitral valve replacement (TMVR) devices are currentlybeing designed and tested clinically to provide therapy to patientssuffering from mitral regurgitation. One potential problem thatpresently is faced by current TMVR devices is their profile andstiffness; another problem is associated with the axial length of thestent frame which can impinge upon the native anterior mitral leafletand cause blockage of the left ventricular outflow tract (LVOT). Thelonger axial length of the current stent frames is needed to support theattachment of the standard TMVR semi-lunar shaped replacement leafletsand provide the necessary strength and lever arm needed to ensure thatthe replacement leaflets do not evert during systole. Much of theprofile for the TMVR devices is related to the thickness of theleaflets; the leaflet thickness is needed to provide the strength neededto support the stresses imposed by the blood pressure onto thereplacement leaflets during systole. Further, the current TMVR devicesoften create stagnation zones that lead to thrombus formation thatresult in the formation and release of harmful thromboemboli. What isneeded is a low profile TMVR device that does not impinge upon thenative anterior mitral valve leaflet and does not have a tendency togenerate potentially harmful thromboemboli.

SUMMARY

The present invention is a transcatheter heart valve with leaflets thatare supported along their free-edge in a manner that is similar indesign to the native mitral valve or the native tricuspid valve found inthe heart. The present invention can be applied to any of the fourvalves of the heart although the present specification will focus on itsapplication to TMVR.

The current transcatheter aortic valve replacement (TAVR) devices havebeen directed toward the semi-lunar valve leaflet designs similar tonative aortic valves of the heart and similar to those used in surgicaltissue heart valves; such replacement devices have been successfullyutilized in the clinic. The attachment of the semi-lunar leaflets to thecylindrical wall of the stent frame follows a crown-shaped pattern thatrequires an axial distance for the attachment in order to provide thestrength and torque lever arm to the leaflet necessary to preventleaflet eversion; the free edges of the semi-lunar leaflets are notattached to the wall of the stent except at points which is referred toas commissures; where the free edge attaches the leaflet to thecylindrical vessel wall; the free edges of the semi-lunar leaflets coaptwith each other at the downstream end of the valve to prevent retrogradeblood flow. The present invention provides a different shape for theleaflets, one that attaches the entire free edge of the leaflet to aseries of cords; the cords are attached to fastening sites that arefixed in space at a location that is downstream of the replacement valveleaflets. The fastening sites serve a similar function to the papillarymuscles found in the human heart; the cords serve a similar function tothe cordae tendineae of the heart. The free edges of the presentinvention also coapt with each other at the downstream end of the valveto prevent retrograde flow of blood.

The attachment of the leaflet base of the present invention to the stentframe follow a linear attachment around a circular or oval shape ratherthan a crown-shaped attachment. The linear attachment does not requirean axial length component to provide torque strength to the valveleaflets to prevent eversion; instead the cords provide the strength toprevent leaflet eversion. The linear attachment allows the length of thestent frame, which supports the replacement leaflets (in the presentembodiment the linear attachment is located adjacent to the mitralannulus) to be shorter than a stent frame that supports a semi-lunarshaped leaflet; the short frame length of the present invention providesan advantage for not causing impingement onto the anterior mitral valveleaflet; such impingement can result in resistance to blood flow in theLVOT. The attachment of the cords to the free edge of the presentleaflets allows the leaflets to be thinner than leaflets used insemi-lunar valves thereby allowing the profile (i.e., delivery diameterfor the device) for the TMVR device to be smaller and more easilydelivered to the proper location across the mitral valve of the heart.Blood flow across the present stent-valve eliminates all regions forpotential blood flow stagnation that can result in the formation ofthrombus.

In one embodiment two supports are extended from each side of the stentframe downstream and into the left ventricle (LV); the supports canextend in a direction that is both downstream and also extending suchthat the supports end at fastening sites that have a smaller distancefrom each other than the diameter of the stent frame that is located inthe mitral valve annulus. The free-edge supported leaflets of thepresent invention are attached at their free edges via cords to thefastening sites. A stent-like structure that forms an expandable frustum(smaller diameter end of frustum is located downstream of the largerdiameter end) is attached to the downstream end of the stent frame. Thesupports are either attached to the expandable frustum, or thestent-like structure of the expandable frustum becomes the supports andthe fastening sites are located at the downstream end of the expandablefrustum.

In an alternate embodiment, three or more supports are attached alongthe perimeter of the stent frame and extend downstream into the LV. Theplurality of supports can be used to support three or more cusps of thefree-edge supported leaflets of the present invention which are attachedvia cords to the plurality of fastening sites.

In still another embodiment the fastening sites can be attached to eachother by a lower support arm which supplies strength and stability tothe fastening site.

In yet another embodiment two or more supports located along theperimeter of the stent frame extend downstream of the stent frame intothe LV but meet at a single fastening point that is located downstreamof the free-edge supported leaflets. The free edges of the plurality ofleaflets are attached to one or more fastening sites via a plurality ofcords.

In still yet another embodiment a single support is attached to thestent frame and extends downstream along a centerline axis of the mitralvalve and stent frame ending in one or more fastening site that arelocated downstream of the replacement leaflets. The free edge of two ormore free-edge supported leaflets are attached via a plurality of cordsto the one or more fastening sites.

BRIEF DESCRIPTION OF THE DRAWING:

FIG. 1A is a perspective view of a native semilunar valve of the hearthaving unsupported free edges.

FIG. 1B is a plan view of native semilunar leaflets splayed out on aflat surface.

FIG. 2A is a perspective view of a native bileaflet heart valve showingthe anterior leaflet attached to two separate papillary muscles.

FIG. 2B is a perspective view of a native bileaflet heart valve showingthe posterior leaflet attached to two separate papillary muscles.

FIG. 2C is a plan view of bicuspid heart valve leaflets splayed out ontoa flat surface and attached to two papillary muscles.

FIG. 3 is a perspective view of the heart showing the native anteriorand posterior valve leaflets attached to the mitral annulus.

FIG. 4A is a perspective view of a stent-valve frame having a waist andhaving supports attached to the waist and extending downstream tofastening sites located at the distal end of the supports.

FIG. 4B is a top view of the stent-valve frame showing the supportsextending inwards to a fastening site distance that is smaller than thewaist diameter.

FIG. 4C is a perspective view of the stent-valve frame having threesupports that are attached to the waist.

FIG. 4D is a top view of the stent-valve frame having three supportsattached to the waist.

FIG. 4E is a perspective view of the stent-valve frame having twosupports that are contiguous with or attached to an expandable frustumframe that extends downstream from the waist.

FIG. 4F is a plan view of the stent-valve frame containing replacementleaflets that have free edges that are attached via cords to fasteningsites on the supports; the stent-valve frame is positioned with thewaist adjacent the mitral annulus.

FIG. 4G is a plan view of the stent-valve frame of FIG. 4F from adirection perpendicular to FIG. 4F.

FIG. 5A is a top view of the native mitral valve annulus having astent-valve frame positioned adjacent the annulus; the stent-valve frameis attached to the replacement leaflets via a linear attachment and thefree edges of the leaflets are attached to the fastening sites viacords.

FIG. 5B is a plan view of the stent-valve frame showing the anteriorreplacement leaflet attached at its free edge via cords to both thelateral fastening site and the medial fastening site.

FIG. 5C is a plan view of the stent-valve frame showing the anterior andposterior replacement leaflets attached at their free edges via cords toone of the fastening sites during diastole with the leaflets in an openconfiguration.

FIG. 5D is a plan view of the stent-valve frame showing the anterior andposterior replacement leaflets attached at their free edges via cords toone of the fastening sites during systole with the leaflets in an closedconfiguration.

FIG. 5E is a perspective view of an anterior replacement leaflet that isattached to both the medial fastening site and the lateral fasteningsite.

FIG. 6A is a perspective view of a stent-valve frame having supportsconnected at their distal ends via a lateral support arm.

FIG. 6B is a top view of the stent-valve frame of FIG. 6A havingsupports connected at their distal ends via a lateral support arm.

FIG. 7 is a perspective view of a stent-valve frame showing an anteriorreplacement leaflet attached via its free edge to a lower support arm.

FIG. 8A is a perspective view of anterior and posterior replacementleaflets having a rim that extends from the anterior and posteriorreplacement leaflet cusps to the rim outer diameter; the anterior andposterior cusps are shown attached via cords to one of the fasteningsites.

FIG. 8B is a perspective side view of replacement leaflets of FIG. 8A ina direction perpendicular to FIG. 8A showing the free edge of theanterior leaflet attached to both the medial and lateral fasteningsites.

FIG. 8C is a plan view of replacement leaflets splayed out flat showingtwo leaflet cusps attached via the free edge to medial and lateralfastening sites.

FIG. 8D is a plan view of replacement leaflets splayed out flat showingthree leaflet cusps attached via the free edge to three separatefastening sites.

FIG. 9A is a plan side view of the stent-valve frame with the free edgesof the replacement leaflets attached to fastening sites via cords; thereplacement leaflets are in an open configuration allowing blood to flowfrom the LA to the LV.

FIG. 9B is a plan side view of the stent-valve frame with thereplacement leaflets in a closed configuration; the replacement leafletsare longer than the native leaflets to ensure that the replacementleaflets will have an exposed area that blood pressure will act upon toclose the leaflets during systole.

FIG. 10A is a plan side view of the stent-valve frame having replacementleaflets attached to the stent-valve frame and in an open configuration;the replacement leaflets have a rim that provides an open space forblood flow and blood pressure access.

FIG. 10B is a plan side view of the stent-valve frame showing ananterior replacement leaflet attached and in a closed configuration; thereplacement leaflets have a rim that provides an open space for bloodpressure access during systole to close the replacement leaflets.

FIG. 11 is a plan side view of the stent-valve frame showing the freeedges of the replacement leaflets attached via cords to one of thefastening sites such that the free edges are held away from the nativeleaflet and providing an open space for blood pressure to act upon thereplacement leaflets for ensuring closure during systole.

FIG. 12A is a perspective side view of the free-edge supportedreplacement leaflets in an open configuration being attached along theleaflet base to the stent-valve frame and attached via the free edges tofastening sites via cords.

FIG. 12B is a perspective side view of the free-edge supportedreplacement leaflets in a closed configuration with the leaflets makingcontact with each other forming a coaptation surface.

FIG. 12C is a plan view of bicuspid replacement valve leafletsidentifying the free edge and the linear attachment path of the leafletthat is made with the stent-valve frame.

FIG. 12D is a perspective view showing the linear attachment path of theleaflet base with the stent-valve frame and the attachment of the freeedges to attachment sites via cords.

FIG. 13A is a plan view of a bicuspid replacement valve leaflets splayedout on a flat surface; the leaflet are formed from polymeric or tissuematrix material and have fibers embedded or attached that extend in acircumferential and axial direction.

FIG. 13B is a plan view showing a fiber embedded in a polymer or tissuematrix.

FIG. 13C is a plan view showing a fiber sandwiched between two filmlayers of polymer material or tissue matrix material.

FIG. 13D is a perspective view of the stent-valve frame attached to thefiber-embedded polymeric or tissue matrix replacement valve leaflets;sutures can attach the replacement valve leaflet to the stent-valveframe; cords can attach to the free edges of the replacement leaflets.

FIG. 13E is a perspective side view of one fiber-embedded replacementvalve leaflet shown in a direction perpendicular from FIG. 13D.

FIG. 14A shows a plan view of splayed bicuspid replacement valveleaflets having embedded fibers that extend outwards in an axialdirection beyond the leaflet base for attachment to the stent-valveframe and extend beyond the free edges for attachment to the fasteningsites.

FIG. 14B is a perspective view of the stent-valve frame havingfiber-embedded replacement leaflets that extend in an axial directionfor attachment to the stent-valve frame and for attachment to thefastening sites.

FIG. 15A is a plan view of leaflet frame that is formed from a thinmetal or polymeric film; the leaflet frame is embedded within orsandwiched between polymeric or tissue matrix material to providesstrength to the replacement leaflets and provide durable attachmentssites for the replacement leaflets.

FIG. 15B is a plan view of a stent-valve frame having replacementleaflets as described in FIG. 15A attached to the stent frame andattached via cords to fastening sites.

FIG. 16A is a plan side view of a single component stent-valve having anattachment mechanism to the mitral valve annulus that contains barbs inan inactive configuration located adjacent an uninflated torus balloon;the stent-valve frame has the base of the replacement leaflet attachedto the stent-valve frame in a linear configuration and the leaflet freeedges are attached to supports via cords.

FIG. 16B is a plan side view of a single component stent-valve having anattachment mechanism to the mitral valve annulus to prevent migration ofthe stent-valve frame that contains barbs in an active configurationlocated outside of the stent-valve frame due to inflation of a torusballoon; the stent-valve frame has the base of the replacement leafletattached to the stent-valve frame in a linear configuration and theleaflet free edges are attached to supports via cords.

FIG. 16C is a plan side view of a single component stent-valve having anattachment antimigration mechanism that has holding arms that extendsaround the native mitral valve leaflets; the stent-valve frame has thebase of the replacement leaflet attached to the stent-valve frame in alinear configuration and the leaflet free edges are attached to supportsvia cords.

FIG. 16D is a plan side view of a single component stent-valve having anattachment antimigration mechanism that has a tether attached to thestent-valve frame, the tether extends through the myocardial tissue nearthe apex and attaches to a button on the outside of the heart; thestent-valve frame has the base of the replacement leaflet attached tothe stent-valve frame in a linear configuration and the leaflet freeedges are attached to supports via cords.

FIG. 16E is a plan view of a stent-valve frame in a small diameterconfiguration within a sheath.

FIG. 17A is a plan view of a dual component stent-valve having a firstcomponent that is attached to the native annulus via barbs that areactivated from inflation of a torus balloon; a second component isplaced in the open central lumen of the first component; the secondcomponent has free-edge supported replacement leaflets; the secondcomponent locks with the first component.

FIG. 17B is a plan view of a dual component stent-valve having a firstcomponent that is attached to the native valve leaflet via holding armsthat extend around the native valve leaflets; a second component isplaced in the open central lumen of the first component; the secondcomponent has free-edge supported replacement leaflets; the secondcomponent locks with the first component.

FIG. 18A is a plan view of a first component of a dual componentstent-valve; the first component has self-expanding barbs are held in aninactive configuration via control fibers as the first component frameis in an expanded configuration.

FIG. 18B is a plan view of a dual component stent-valve of FIG. 18Ahaving a first component that is attached to the mitral valve annulusvia self-expanding barbs that are activated via release of the controlfibers after the first component is in an expanded configuration; asecond component is placed in the open central lumen of the firstcomponent; the second component has free-edge supported replacementleaflets; the second component locks with the first component to preventmigration of the second component.

DETAILED DESCRIPTION:

FIGS. 1A and 1B show a native semi-lunar valve (10) that is similar tothe native valves found in the aortic and pulmonary positions within theheart and also found in most surgical tissue valves and in most TAVRdevices. The leaflet cusps (20) or leaflets are attached at the leafletcrown-shaped attached edge (30) to the wall of the tubular structurewall (40) in a crown-shaped attachment (50). The unsupported free edges(60) of the leaflets are not attached to the wall of the supportstructure except at the location of the commissures (70) and theunsupported free edges (60) do not have any cordae tendineae or cordsattached to them. The central free edge (80) of one leaflet forms acentral junction (90) with the central free edge of another leafletwithout any attachment to the support structure at the central junction.

FIGS. 2A-2C show native mitral valve leaflets (100) that have a linearattachment (120) to the mitral annulus (130) along a linear shape thatforms a circle, oval path, or saddle-shaped path; the linear attachmentis not a crown-shaped attachment path as found in semi-lunar valves suchas native aortic valves; such semi-lunar valves have a crown-shapedattachment with axial componency that supports the leaflet fromeverting. A rim (140) of leaflet tissue extends from 2-6 mm along theperimeter of the mitral valve annulus (130) and extends toward theleaflets and forms two or more native leaflets (100) with native leafletcusps (20) (i.e., 3 cusps for the tricuspid valve). As shown in FIG. 2Athe supported free edge (150) of the anterior leaflet (160) is attachedvia cordae tendineae (170) to the anterior (or lateral) papillary muscle(180) and posterior (or medial) papillary muscle (190). The supportedfree edge (i.e., supported by and attached to the cordae tendineae(170)) moves into contact with the supported free edge of another mitralvalve leaflet during systole to prevent blood flow from passing from theLV (240) to the LA (230) (shown in FIG. 3); the supported free edge ofone leaflet moves away from another leaflet during diastole to allowblood to flow distally (940) through the valve. More than one cordae canattach from a papillary muscle to the anterior leaflet, for example;individual cordae can attach to an intermediate free edge (200), acentral free edge (80), or other attachment sites along the free edge ofa particular leaflet. FIG. 2B shows the posterior mitral leaflet (165)and the free edge attached to the posterior and anterior papillarymuscles. The rim of the anterior and posterior leaflets is attached tothe mitral annulus (130) along a linear circular, oval, or saddle-shapedpath that is not crown-shaped.

FIG. 3 shows a view of the heart (210) with the native mitral valve(220) located between the left atrium, LA (230) and the left ventricle,LV (240). The LVOT (250) directs blood flow from the LV (240) across theaortic valve (260) and into the aorta (265). It is noted that theanterior mitral valve leaflet (160) serves as both a mitral valveleaflet valve function to direct blood flow from the LA (230) to the LV(240) as well as provide one side of the LVOT passage duct duringsystole. If the anterior leaflet is pushed into the LVOT during systole,blood flow through the LVOT will be restricted resulting in poor patientoutcomes.

FIGS. 4A and 4B show one embodiment of the stent-valve frame (270) foruse as one portion of a stent-valve (275) the present invention whichcontains free-edge supported replacement leaflets (280) (or herein alsoreferred to as replacement leaflets) attached to the stent-valve frame(270) in a manner that is similar to the attachment of native mitralleaflets to the mitral annulus (130) and to the cordae tendineae of thebody. The stent-valve frame (270) can be formed from a balloonexpandable (BE) material such as stainless steel or a self-expandingmaterial such as Nitinol, for example. The wall structure (290) orpattern for the stent-valve frame (270) can be similar to stent patternsused in current vascular stents or current TAVR devices includingzig-zag stent structures, closed cell structures, open cell designs, orother stent designs used for stents and stented valves in thevasculature. The waist (300) of the stent-valve frame (270) is thatportion of the stent-valve frame (270) that comes into full contact (orapproaches full contact) along its entire perimeter with the mitralvalve annulus (130) and may also contact a portion of the base of theleaflets; the waist can have a cylindrical shape, a curved shape such asa concave shape (i.e., the waist can curve inwards toward the inside ofthe stent frame, for example) or it can have a tapered shape such as asurface of a frustum (400). The waist (300) of the stent-valve frame(270) can have a short waist axial length (310) (range 2-5 mm) due tothe linear attachment of the leaflets, or the waist can have a longeraxial length (310) (range 5-10 mm) such that it can be positionedadjacent to the mitral annulus and other neighboring native valvetissues. The attachment of the leaflet base (550) of the free-edgesupported replacements leaflets (540) (see FIG. 5A, for example) of thepresent invention to the stent-valve frame (270) has a linear attachmentalong the stent-valve frame perimeter (320) forming a linear replacementleaflet attachment (620) that is an oval or circular attachment to thestent-valve frame (270); the attachment is not crown-shaped.

Various stent-valve frame designs and methods can be used with thepresent invention to attach the stent-valve frame (270) to the annulus(130) or native mitral valve tissues to prevent migration of thestent-valve frame (270) that houses the free-edge supported replacementleaflets (540). A more detailed description of attachment methods can befound in the patent applications that are referenced herein and arefully incorporated into the present patent application by reference;such attachment methods include suturing, adhesive bonding, solventbonding, and other attachment methods. Additional examples of attachmentdesigns that are compatible with the present free-edge supportedstent-valve frame (270) and free-edge supported replacement leaflets(540) are shown later in this patent specification. The stent-valveframe (270) of the present invention can be a single componentstent-valve frame that has the leaflets attached to it and having thestent-valve frame that is attachable directly to the native mitral valvetissue. Alternately, the stent-valve frame (270) of the presentinvention can be a second component or valve-containing member that isplaced into an open central lumen of a first component or support memberthat is initially placed into the native mitral tissues and attached tothe native mitral tissues. The second component is then locked viageometrical fit or via friction to the first component such that thesecond component is unable to migrate toward the LA (230) or LV (240) asdescribed in further embodiments of this patent application.

Attached to the waist of the stent-valve frame (270) along oppositesides of the waist of one embodiment (FIGS. 4A and 4B), approximately180 degrees apart from each other along a stent-valve frame perimeter(320) and extending downstream (330) for a distance of 1.5-3 cm are twosupports (340) that end in two fastening sites (350), a lateral (oranterior) fastening site (360) and medial (or posterior) fastening site(370). The supports (340) extend inward to a smaller diameter such thatthe fastening site distance (380) between the lateral fastening site(360) and medial fastening site (370) is smaller than the mitral annulus(130) by several millimeters and smaller (range 5-20 mm smaller) thanthe waist diameter (390) at the mitral annulus; the supports (340) donot extend into the LVOT as described in FIG. 3 and thereby do not causeany resistance to blood flow out of the LVOT. In an alternate embodimentfor the stent-valve frame (270) three supports (340) are attached to thestent-valve frame (270) and extend downstream (330) as shown in FIGS. 4Cand 4D. Each of the three supports (340) ends in a separate fasteningsite (350). Also, as noted in alternate embodiments, the supports (340)can be a portion of the stent-valve frame (270) that extends downstream(330) of the free-edge supported replacement leaflets (280).

As shown in FIGS. 4E-4G an upstream end (405) of an expandable frustumportion (400) or frustum (400) of the stent-valve frame (270) isattached to the waist downstream end (410) of the stent-valve frame(270). The expandable frustum (400) can be used to house all or part ofthe free-edge supported replacement leaflets (280); the replacementleaflets (280) can be attached to and partially housed within the waistof the stent-valve frame. The stent-valve frame (270) of the expandablefrustum (400) can also provide the wall structure (290) that serves asthe supports (340) or provides an attachment structure for supports(340); the supports therein providing fastening sites (350) which areused to hold the free edges (540) of the free-edge supported replacementleaflets (280). The expandable frustum (400) has a stent-like wallstructure (290) formed from a SE or BE material that is similar to thatused to form the waist (300) of the stent-valve frame (270) which islocated adjacent to the mitral annulus (130). The expandable frustum(400) can be formed such that it is contiguous with the waist or theexpandable frustum (400) can be attached to the waist of the stent-valveframe (270) via welding, brazing, sutures, adhesives, or otherprocessing methods and materials used to attach expandable structuressuch as vascular stents or other implanted medical devices. Theexpandable frustum (400) forms a smaller frustum outlet diameter (430)(range 5-20 mm smaller) at the frustum downstream end (440) than thewaist diameter (390) at the waist downstream end (410). The expandablefrustum outlet diameter (430) or frustum downstream diameter (430) issmaller (range 5-20 mm smaller) than the diameter of the mitral annulusor the stent-valve frame diameter (390) that is located within themitral annulus (130). The expandable frustum (400) does not impinge uponthe native or anterior mitral valve leaflet or push the leaflet towardthe LVOT and does not cause any restriction in blood flow out of theLVOT (250).

The expandable frustum (400) has a highly open wall structure (450) thatallows for blood flow (460) through the stent-like wall structure (290)of the expandable frustum (400) in regions that do not contain acovering. The expandable frustum (400) holds the native mitral valveleaflets (100) outwards (465) and out of direct contact with thereplacement mitral valve leaflets (280). The native mitral valveleaflets are provided with blood flow through the open wall structure(450) of the expandable frustum (400) during systole when thereplacement leaflets (280) are in a closed configuration 608) (see FIG.5D, for example). A recirculation space (470) for recirculatory bloodflow (480) is maintained between the native mitral valve leaflet and thewall of the LV (240) due to the frustum-like shape of the expandablefrustum (400) which has a smaller frustum downstream diameter (430) thanthe frustum upstream diameter (435) as shown in FIG. 4G. Therecirculatory blood flow (480) between the native mitral valve leafletsand the wall of the LV (240) will ensure that blood flow stagnation doesnot occur and that thromboemboli are not generated. Healing of thenative valve leaflets into contact with the outer surface (485) of theexpandable frustum (400) can hold the native valve leaflets in aposition adjacent to the wall of the frustum (400); such a position willnot generate thromboemboli due to recirculatory blood flow (480) anddirected blood flow (460) through the open wall structure (450) of thefrustum (400). Alternately, the native valve leaflets can continue toflex from a position near the LV lateral wall (495) or within the LVOT(250) during diastole and flex into contact with the frustum shapedframe during systole. FIG. 4F shows a side view of the stent-valve frame(270) positioned adjacent to the annulus and viewing one free-edgesupported leaflet (280) that is attached, as a viewing example; theleaflet is attached to fastening sites (350) located at the distal ends(490) of two supports (340) via a plurality of cords (500) that extendfrom a fastening site (350) on the support (340) to a leaflet attachmentsite (545) located along a free edge (540) of the replacement leaflet.FIG. 4G shown a side view of the stent-valve frame in a directionperpendicular to that of FIG. 4F; each of the two replacement leaflets(280) are attached via a plurality of cords (500) to both of thefastening sites (350).

The supports (340) can be attached to the expandable frustum (400) or tothe waist of the stent-valve frame (270) via welding, soldering,brazing, mechanical attachment methods, adhesives, or other bondingmethods. Alternately, the supports (340) can be contiguous with theexpandable frustum (400); the wall structure (290) of the expandablefrustum (400) can become the supports (340) or serve as the supports.Two or three locations located along the perimeter of the downstream end(440) of the expandable frustum (400) can become the fastening sites(350) to which the cords (500) are fastened; the opposite ends of thecords (500) (opposite to the fastening site ends) are then attached tothe free edges (540) of the replacement leaflets (280). Thus, thesupports (340), can be a formed, for example, by the wall of theexpandable frustum (400) and the fastening sites (350) can be specificlocations at or near the downstream end of the expandable frustum (400).

As shown in FIGS. 5A-5E the rim (568) of the free-edge supportedreplacement leaflets (280) are attached at the replacement leaflet base(550) along a linear replacement leaflet attachment (630) that follows alinear path of a circle or oval along a perimeter of a replacementleaflet base (550) attached to the stent-valve frame (270). Thestent-valve frame follows the circular or oval shape of the nativemitral annulus (130). The rim (568) of the free-edge supportedreplacement leaflets (280) extends radially inwards to form a free-edgesupported anterior replacement leaflet (285) and a free-edge supportedposterior replacement leaflet (288). The free edge (540) of the anteriorleaflet is attached via a plurality of cords (500) to both the lateralfastening site (360) and the medial fastening site (370) located at thedistal end (490) of the supports (340). The free edge (540) of theposterior leaflet is attached via a plurality of cords (500) to both thelateral fastening site and the medial fastening site. The anteriorreplacement leaflet (285) has a central free-edge region (510) that hasa plurality of cords (500) some of which attach to the medial fasteningsite and some of which attach to the lateral fastening site. Theanterior leaflet has an intermediate lateral free-edge region (520) thatattaches to the lateral fastening site, for example.

The leaflets of the present invention are formed from pericardialtissue, xenograft heart leaflet tissue, polymeric film, or compositethin members that can function as a heart valve leaflet. A compositeleaflet can be formed from a leaflet frame that is embedded orsandwiched within a polymeric or tissue matrix film as described inlater embodiments for the leaflet. The leaflet frame be formed of metalor polymeric material and can be attached via the leaflet free edge(540) to cords (500) and the leaflet frame can also be attached alongthe leaflet base (550) to the stent-valve frame (270) using metaljoining methods or polymer bonding methods. FIG. 5B shows a sectionalview of the stent-valve frame (270) and supports (340) with thereplacement leaflet free edge (540) of the anterior leaflet attached viaa plurality of cords (500) to the medial fastening site (370) or lateralfastening site (360). FIG. 5C shows a sectional view (rotated by 90Degrees from FIG. 5B) of the stent-valve frame (270) with the anteriorreplacement leaflet (285) and posterior replacement leaflet (288) in anopen configuration (606) such as found during diastole. The anteriorreplacement leaflet is attached at the replacement leaflet base (550) tothe inlet end (405) or upstream end (405) of the frustum (400). FIG. 5Dshows a sectional view (rotated by 90 Degrees from FIG. 5B) of thesupport structure with the anterior replacement leaflet (285) andposterior replacement leaflet (288) in a closed configuration (608) suchas found during systole. FIG. 5E shows a perspective view of theanterior replacement leaflet (285) attached via a central free-edgeregion (510) and an intermediate free-edge region (520) to a medialfastening site (370) and a lateral fastening site (360).

FIGS. 6A and 6B shows an embodiment of a stent-valve frame (270) thathas two fastening sites (350) that are intended to provide attachment ofcords (500) (shown in FIGS. 5A-5E) that attach to replacement leafletfree edge (540) of a bicuspid valve having free-edge supportedreplacement leaflets (280) as described in FIGS. 5A-5E. In thisembodiment, the two fastening sites (350) are attached together via alateral support member (560) or lateral support arm. The medial supportmember holds the medial fastening site (370) at a specific fasteningsite distance (380) from the lateral fastening site (360) and providesstructural stability to the supports (340). The fastening site distanceis smaller (range 5-20 mm smaller) than the diameter of the mitralannulus (130) and smaller (range 5-20 mm smaller) than the waistdiameter (390) of the stent-valve frame (270) that is located in theannulus. Other stent-valve frame structures are anticipated that providefastening sites (350) located downstream (330) of the mitral annulus(130) and downstream (330) of the replacement leaflets (280) to holdcords (500) that attach to the replacement leaflet free edges (540). Anexpandable frustum (400) may be attached to the waist of the stent-valveframe (270) that is described in FIGS. 6A, 6B, 5A-5E, and in FIGS.4E-4G, the supports (340) can be independent from the frustum (400)stent-valve structure or the supports (340) can be attached orcontiguous with the frustum stent-valve wall structure (290).Alternately, as described in earlier embodiments, the supports (340) canbe attached to and extend downstream (330) from the waist (300) to alocation distal to the replacement leaflet free edge (540) forattachment of the replacement leaflet free edge (540) via cords (500)without the presence of a frustum-shaped frame (400).

FIG. 7 shows an embodiment for a stent-valve frame (270) for astent-valve (275) having a support (370) that is attached to the waist(300) of a stent-valve frame (270) via an upper support member (562) anda central shaft (565) that extends downstream (330) of the stent-valveframe (270) along a centerline (564) of the stent-valve frame to alocation downstream (330) of the free edge (540) of the replacementleaflets (280). One or more fastening sites (350), attached directly tothe central shaft (565) via a lower support arm (566), are attached tocords (500) that then attach to the free edge (540) of free-edgesupported leaflets. Alternately, a single central shaft (565) can extendalong a centerline (564) of the stent-valve frame (270) to a centralsite (567) downstream (330) of the replacement leaflets (280). One, two,three, or more fastening sites (350) attached directly or indirectly tothe central site (567) of this central shaft (565) can be used to holdcords (500) that are then attached at the opposite ends of each of thecords (500) to the free edges (540) of the replacement leaflets (280).

The valve leaflet assembly (280) or replacement leaflets (280) arecomprised of the leaflet rim (568) plus the leaflet cusps; for thepresent invention the leaflet assembly (280) can be comprised of twoleaflets, three leaflets, or more than three leaflets; each leafletbeing comprised of a portion of a replacement leaflet rim (568) plus areplacement leaflet cusp (570) (see FIGS. 8A-8B). As shown in FIGS.8A-8C this valve embodiment contains two leaflets, an anterior leaflet(285) and a posterior leaflet (288) that are supported along thereplacement leaflet free edges (540) by cords (500) which are attachedvia leaflet attachment sites (545) to one end of the cords; the oppositeends of the cords (500) are attached to fastening sites (350). Eachleaflet of the present embodiment and other embodiments of the presentinvention is attached to at least one cord but preferably is attached to2 or more cords (500). The cords (500) of the present invention can beconstructed from a polymeric fiber such as polytetrafluoroethylene(PTFE), polyethylene terephthalate (PET) or other strong, high tensilestrength, flexible, biocompatible fiber formed via a monofilament ormultifilament structure; alternately, the cord can be formed from metalstrands formed from stainless steel, for example, or composite strandsincluding multifilament strands.

The central free edge regions (510) for the anterior replacement leafletcusp (580) is attached to a lateral fastening site (360) and a medialfastening site (370). Similarly, the posterior replacement leaflet cusp(582) is attached to a lateral fastening site and a medial fasteningsite. The anterior replacement leaflet (285) has an anterior rim (572)that is contiguous with and forms a portion of the anterior replacementleaflet; the anterior rim is contiguous with the anterior replacementleaflet cusp (580). The replacement leaflet base (550) is attached tothe stent-valve frame (270) via attachment means which include sutures,adhesive bonding, and other attachment means known in the industry. Theposterior replacement leaflet has a posterior rim (574) that iscontiguous with and forms a portion of the posterior replacement leaflet(288); the posterior rim (574) is contiguous with the posterior leafletcusp (582); the posterior rim extends to the leaflet base (550) that isattached to the stent-valve frame (270). The anterior rim (572) and theposterior rim (574) form a leaflet assembly rim or replacement leafletrim (568) that extends with a rim width (576) around the entireperimeter of the valve leaflet assembly forming the perimeter of thereplacement leaflet base perimeter (578). The anterior leaflet cusp(580) is separated from the posterior leaflet cusp (582) forming aseparate replacement leaflet cusps (570) downstream (330) from theleaflet assembly rim. The rim width for the present invention is 4 mm(range 2-10 mm). The replacement leaflet length (584) for the anteriorleaflet or posterior leaflet extending along an integrated path from theattachment of the leaflet to the stent-valve frame (270) at the leafletbase to the leaflet central free-edge region (510) is 2 cm (range1.5-2.5 cm). The rim outer diameter (588) located at the attachment ofthe rim (568) with the stent-valve frame (270) is equal to the diameterof the stent-valve frame; the stent-valve waist diameter (390) is equalto the diameter of the mitral valve annulus or native valve tissues towhich the stent-valve frame (270) is attached; the mitral annulus (130)is typically 35 mm in diameter (range 28-45 mm). The rim inner diameter(590) at a location between the leaflet assembly rim (568) and theanterior/posterior cusps is 8 mm smaller (range 4-20 mm smaller) thanthe outer rim diameter. The replacement leaflet rim (568) serves toprovide a continuous layer of leaflet material that is impermeable toblood flow and that provides a seal to prevent blood regurgitation nearthe perimeter of the anterior replacement leaflet (285) and posteriorreplacement leaflet (288) during leaflet coaptation in systole. The freeedge supported replacement leaflets (280) of the present invention arenot required to have a rim (568); the leaflets cusps can extend to theleaflet base and attach to the stent-valve frame (270). The leafletassembly for the embodiment of a bicuspid valve can be seen splayed outflat in FIG. 8C. The individual valve leaflets as shown are attached totwo fastening sites (350), the lateral fastening site (360) and themedial fastening site (370); additional fastening sites (350) can bedesignated for a valve leaflet if desired. FIG. 8D shows a tricuspidvalve leaflet assembly of the present invention in a splayed out manner.The tricuspid valve assembly contains three fastening sites (350) asshown in this embodiment, although additional fastening sites (350) canbe provided without deviating from the present invention.

One important aspect of the present invention is the structure of thestent-valve (i.e., stent-valve frame plus replacement leaflets (280)needed to ensure that the replacement leaflets (280) of the presentinvention are readily closed during the high pressure systolic cycle ofLV (240) heart contraction; additionally the replacement leaflets (280)should not provide regions of blood stagnation that could lead tothrombus formation. FIGS. 9A and 9B show an embodiment of thestent-valve (275) placed with the stent-valve frame (270) adjacent themitral annulus (130). The native mitral leaflets (100) and thereplacement leaflets (280) are shown in an open configuration (606)allowing blood to flow downstream (330) through the valve duringdiastole in FIG. 9A. The replacement leaflets (280) are held by cords(500) which are attached to fastening sites (350) located on thestent-valve frame (270) which can serve as the supports (340) or tosupports (340) which can be attached as supports (340) to thestent-valve frame (270) as described earlier. During systole (see FIG.9B) as blood pressure is increasing the replacement leaflets (280) ofone embodiment having a longer replacement leaflet length (584) than thenative leaflet length (586) (extending from the mitral annulus (130) tothe native leaflet free edge (150)) are forced into a closedconfiguration (608). The replacement leaflet length (584) of thisembodiment are 4 mm longer (range 2-8 mm longer) than the native leafletlength (586) or are positioned with a portion of the replacement leafletfree edge (540) downstream (330) of the native leaflet free edge (150)to ensure that blood pressure within the LV (240) is acting on anexposed area (592) of the replacement leaflets (280) that cannot beblocked by the native leaflets even if the native leaflets are orienteddirectly adjacent to the replacement leaflets (280). The stent-likestructure of the expandable frustum (400) will hold the native leafletoutwards (465) during systole as the native leaflet is pushed intocontact with the frustum (400) due to the LV (240) blood pressure. Thefrustum length (594) is longer than the replacement leaflet length (584)to provide a fastening site (350) at a location downstream (330) fromthe replacement leaflet free edge (540) from which a cord can beattached from the fastening site (350) and the opposite end of the cordattached to the leaflet central free edge region (510) of thereplacement leaflet (280).

In other embodiments the replacement leaflets (280) have the samereplacement leaflet length (584) as the native leaflet length (586) andcan alternately be smaller in replacement leaflet length (584) than thenative leaflet length (586). An alternate embodiment for the stent-valve(275) including the leaflet assembly (280) is shown in FIGS. 10A and10B. In this embodiment the replacement leaflet rim (568) is formed suchthat it is attached to the waist but does not make contact (along mostof the perimeter) with the wall structure (290) of the expandablefrustum (400). In this embodiment the replacement leaflet length (584)is similar or shorter than the native leaflet length (586) extendingfrom the annulus (130) to the native leaflet free edge (150). Theleaflet assembly rim (568) extends from its attachment to the waist(300) of the stent-valve frame (270) inwards toward the devicecenterline axis (564) for a distance equal to the rim width (576) toreach the rim inner diameter (590). Located farther downstream (330) ofthe replacement leaflet rim (568) are the replacement leaflet anteriorcusp (580) and replacement leaflet posterior cusp (582). Blood flow(460) and blood pressure during systole will always have an open pathwayto deliver high pressure blood through the open wall structure (450) ofthe expandable frustum (400) and into the open space (596) that islocated between the expandable frustum and the replacement leaflets(280) and thereby closing the replacement leaflets (280) during systole.FIG. 10B shows the stent-valve in a lateral view that is 90 degrees outof phase from FIG. 10A; the blood pressure and blood flow path (460)into the open space (596) cannot be blocked even if the native valveleaflets (100) are aligned adjacent to the replacement valve leaflets(280).

In a further embodiment shown in FIG. 11, the replacement leaflets (280)are held by the cords (500) such that the replacement leaflets (280) donot come into contact with the stent-like wall structure (290) of theexpandable frustum (400) as shown during diastole when the replacementleaflets (280) are in an open configuration (606). Cords (500) attachedto the leaflet central region (510) on one end of each of the cords andattached to the fastening sites (350) on the opposite end of the cords(500) hold the leaflet free edge (540) of this embodiment with a tension(598) that does not allow the replacement leaflets (280) to contact thewall structure (290) of the expandable frustum (400) during diastole. Inthis embodiment during systole, the blood flow (460) and blood pressurewill always have a direct path through the open wall structure (450) ofthe expandable frustum (400) to the downstream (330) side of thereplacement leaflets (280) to the open space (596) to provide a pressureforce against the replacement leaflets (280) to drive the replacementleaflets closed and into coaptation (or contact of the leaflet cusps)with each other. The native leaflets (100) cannot block the blood flow(460) from reaching the downstream (330) side of the replacementleaflets (280) even if the native leaflets are positioned identicallyadjacent to the replacement leaflets (280). Thus the stent-valve frame(270) of the present invention is not required to be oriented in acircumferential direction (600) as the stent-valve frame is positionedwithin the native annulus (130) and native tissues of the native heartvalve.

It is understood that embodiments that lengthen the replacement leafletlength (584) or form an open space (596) between the replacementleaflets (280) and the expandable frustum (400) as described in previousembodiments are not necessary if the operator is willing to orient thereplacement leaflets (280) of the present invention such that thereplacement anterior leaflet (285) is not placed adjacent to the nativeanterior leaflet (160) and the replacement posterior leaflet (288) isnot placed adjacent to the native posterior leaflet (165). Suchorientation of the stent-valve of the present invention will allow bloodflow and blood pressure to have a direct pathway to the downstream (330)side of the replacement leaflets (280) during systole and allow thereplacement leaflets (280) to close properly. Furthermore it isunderstood that the high blood velocity extending in a retrograde orupstream (865) direction (i.e., opposite to downstream (330) direction)through the open replacement leaflets (280) of the stent-valve of thepresent invention at the start of systole will be associated with a lowpressure (via energy conversion described by Bernoulli Equation) thatwill have a tendency to pull the replacement leaflets (280) of thepresent invention into a closed configuration (608) during systolewithout the need for a length increase (relative to the native leafletlength) for the replacement leaflet length (584) or creating a presenceof an open space (596) as presented herein.

The replacement leaflets (280) for the present invention can be formedfrom tissues taken from animal pericardium, xenograft heart valve,allograft heart valve, or other tissue or collagen materials.Alternately, the replacement leaflets (280) can be formed from a thinlayer of polymeric material such an expanded polytetrafluoroethylene(ePTFE), Dacron film, polymeric woven, braided, or knitted material.Alternately, polymeric material, collagen tissue, and other tissuematerial can be used by themselves or in combination with othermaterials including and embedded leaflet frame or embedded fibers toform a composite replacement leaflet of the present invention. Often apolymeric or tissue material that is exposed to continued stress willtend to creep, therefore many of the polymeric films and some of thetissue or collagen materials used for valve leaflets will need to besupported by fibers or films made from stronger materials that will notcreep under stress. Also support fibers or films can be used to provideattachment strength to the replacement leaflet such that the leafletdoes not break or tear under stresses from blood pressure or form aleakage site. Such stronger support fibers and films include Dacronfibers, thin multifilament metal fibers, thin metal films such asNitinol films and other materials of similarly high tensile strength andlow creep; such films and fibers can have diameters and thickness of0.001 inches (range 0.0003-0.002 inches) and can be very flexible.

The replacement leaflet base (550) of the free-edge supported valveleaflets of the present invention is attached to the wall of astent-valve frame (270) in a linear replacement leaflet attachment path(630) that is a round circle or oval as shown in FIG. 12A. Thereplacement leaflet free edge (540) of the replacement leaflet (280)comes into direct contact with a neighboring leaflet cusp (570) and aportion of the valve leaflet coapts with the neighboring leaflet forminga coaptation surface (602) or coaptation region in a closed leafletconfiguration (608) as shown in FIG. 12B. The free edges (540) of eachof the leaflets are attached via cords (500) to two fastening sites(350) as described in earlier embodiments; the fastening sites arelocated at the distal ends (490) of two supports (340) that are attachedto the stent-valve frame as described in earlier embodiments of thepresent invention or the fastening sites form a local region of thestent-valve frame. The supports (340) can extend along two or more sidesof a frustum-shaped housing along the length of the frustum (400) andform fastening sites (350) for the cords (500) at their downsteam ends.The supports (340) can also attach to a waist of the stent-valve frameand extend distally (940) to the fastening sites (350) without thefrustum stent-valve frame.

The replacement leaflet surface (604) changes shape as the leaflet movesfrom an open configuration (606) as shown in FIG. 12A to a closedconfiguration (608) as shown in FIG. 12B. The leaflets flex viaextension in both the axial flex direction (610) and the circumferentialflex direction (612) as they move from an open position to a closedposition. The axial flexibility characteristics for the leaflet candiffer from the circumferential flexibility characteristics by alteringthe material and dimensions for the axial fibers relative to thecircumferential fibers. Leaflet support fibers can be located within thewall structure of polymeric or tissue leaflets to allow leafletexpansion to occur in a controlled manner and with a controlled leafletshape; also, support fibers provide an attachment region by which thereplacement leaflets (280) can be attached to the stent-valve frame(270) of the present invention; also, the support fibers strengthen thefree edge (540) of the leaflets to prevent the free edge (540) fromencountering irreversible stretching. An embodiment for two free-edgesupported leaflets or leaflet cusps that are found as replacementleaflets (280) in the present free-edge supported stent-valve device isshown in a splayed-out manner in FIG. 12C. The linear replacementleaflet attachment path (630) for attached edge or replacement leafletbase (550) of the leaflets is shown; the linear attachment path can beattached to the stent-valve frame along the waist perimeter (620) orother stent-valve frame perimeter (320) via a variety of attachmentmeans including sutures, adhesives, and other attachment means. Althoughthe present invention is described for two free edge supportedreplacement leaflets, the free-edge supported stent-valve of the presentinvention can be formed with three or four leaflets, instead of two, forexample, without deviating from the present invention.

One embodiment for the free-edge supported replacement leaflets (280) ofthe present invention is shown in FIG. 13A-13C. This replacement leaflet(280) is formed from a polymeric film or tissue matrix that is formedvia either a film casting process, an extrusion process, or other filmforming process. In this embodiment fibers (640) formed from Dacron,Nitinol, stainless steel or other high tensile and low-creep material,for example, are embedded within the polymer or tissue matrix (650) ofthe leaflet polymeric or tissue matrix film, such as polyurethane,collagen, acellular matrix, or cellular tissue, for example, as shown inFIGS. 13A and 13B. The fibers include circumferentially oriented fibers(660) and axially oriented fibers (670). A free-edge fiber (680) canextend along the free edges (540) of the replacement leaflets (280) in acircumferential direction (600); an attachment-edge fiber (690) canextend along the attached edge or replacement leaflet base (550) of theleaflets in a circumferential direction. One or more axial fibers (670)can extend with a substantial axial componency in the axial direction(700) from the free-edge fiber to the attachment-edge fiber. Axialfibers (670) can be attached to free-edge fibers (680) orattachment-edge fibers (690) at fiber attachment sites (710) viabrazing, soldering, welding, adhesives, or other bonding methods. Thecircumferentially oriented fibers (660) and axially oriented fibers(670) can be embedded within the polyurethane or tissue matrix (650);the polymer matrix or tissue matrix can be solvent cast or thermallycast around the fibers (640) as shown in FIG. 13B. Alternately, twoseparate films (720) of polyurethane or tissue material can be placedonto each side of the fibers (640) and heated to thermally bond the twofilm layers together or bonded together via adhesives, solvent bonding,or other bonding method around the fibers to form a sandwich of thepolymer or tissue film on each side of the fibers forming a film bond(722) as shown in FIG. 13C.

The polymer (or tissue) and fiber composite replacement leaflets (725)can then be attached to the waist (300) or to the stent-valve frame(270) via a variety of methods. Sutures (730), for example can be usedto sew the attachment-edge fiber (690) to the stent-valve frame (270) asshown in FIG. 13D and 13E; FIG. 13D is a side view of the stent-valveand FIG. 13E is a side view that is perpendicular to the view of FIG.13D showing the composite replacement leaflet (725) attached to thestent-valve frame (270) of the present invention. Alternately, thepolymer or tissue matrix used as the leaflet film can be used also as acovering (740) for the stent-valve frame (270). A covering (740) isattached to the stent-valve frame (270) of the present invention tocover a portion of the stent-valve frame to prevent blood leakage pastthe stent-valve from the LV (240) to the LA (230). The waist (300),upper bulb (820) and a portion of the frustum (400) of the stent-valveframe (270) can have a covering (740) attached to it. The polymer ortissue matrix of the composite replacement leaflet can be thermallyjoined, solvent bonded, adhesively bonded, or otherwise attached to thestent-valve frame covering (740). Other materials can be used as acovering (740) material including but not limited to expandedpolytetrafluoroethylene (ePTFE), polyethylene terephthalate, Dacron, andNylon films and weaves of fibers formed from such polymer materials.

The composite replacement leaflet (725) can be joined to the stent-valveframe forming a linear attachment (630) via polymer to polymer (ormatrix to matrix) bonding methods which include thermal bonding, solventbonding, adhesive bonding, and other forms of bonding. The replacementleaflet free edges (540) can be attached to cords (500) at thefiber/edge attachment site (710); the cords (500) are then attached attheir opposite ends to fastening sites (350); the cords (500) therebyfunctioning to prevent eversion of the leaflets in a direction towardsthe LA during systole. Attachment of the cords (500) to the fiber/edgeattachment sites (710) can be performed via forming a loop or knot madewith sutures, for example, around the fibers that form the fiberattachment site, using adhesives, brazing, thermal bonding, or othermethods available. The cords (500) can be formed from polymeric ormetallic monofilament or multifilament strands; the cords (500) can beattached to the fastening sites (350) using adhesives, sutures, forminga loop, and other bonding methods.

Another embodiment for attaching the polymer or tissue matrix and fibercomposite replacement leaflets (725) to the stent-valve frame (270) isshown in FIGS. 14A-14B. In this embodiment the axial fibers (670) areallowed to extend beyond the attached-edge fiber (690) forming anattached edge extension fiber (750) as shown in FIG. 14A. Theattached-edge extension fiber (750) can then be attached directly to thestent-valve frame (270) via brazing, welding, swaging, adhesive bondingor other bonding methods available; the axial fibers (670) canalternately be formed to be contiguous with the stent-valve frame (270).The axial fiber (670) can extend beyond the free edge fiber (680)forming a free-edge extension fiber (760). The circumferential fibers(660) can extend beyond the edge of the polymer matrix of the compositereplacement leaflet (725 forming circumferential extensions (765) thatcan be used form the composite leaflet (725) into a circular shape or toattach the composite leaflet (725) to the stent-valve frame (270). Thefree-edge extension fiber (760) can be attached directly to the cords(500) via forming a knot, weld, or adhesive bond; alternately, the axialfiber free-edge extension (760) can extend all the way to the fasteningsite (350) where it is attached to the fastening site (350) via brazing,adhesive bonding, swaging, forming a loop or knot, or other attachmentmethods as shown in FIG. 14B.

A thin film of Nitinol or other metal, or other leaflet frame film (775)can be cut via laser, electric discharge method (EDM) or other methodsto form a leaflet frame (770) that is splayed out as shown in FIG. 15A;the circumferential members (780) of the leaflet frame (770) are thenformed into a circular shape and attached to the waist (300) of thestent-valve as shown in FIG. 15B. The leaflet frame can have axialmembers (790) and circumferential members (780); the circumferentialmembers can extend along the free edge (540) forming free-edge members(800) and along the attached edge forming attachment edge members (810);axial members can extend from the free-edge members to the attached-edgemembers and can be contiguous with them. The leaflet frame can beembedded within a polymer or tissue matrix as described earlier for thefiber supported composite replacement leaflet (725), alternately theleaflet frame can be sandwiched between to polymer films or tissuematrix films via thermal, solvent, adhesive, other bonding method usedto bond two films together. The leaflet frame (770) of the compositeleaflet (725) can be attached to the stent-valve frame (270) viasutures, adhesive bonding, thermal bonding, welding, brazing, soldering,or other methods as described for the polymeric film or tissue matrixthat contained fibers embedded or sandwiched within its wall thickness.Alternately, the leaflet frame can be contiguously formed along with thestent-valve frame (270), the leaflet frame extending withoutdiscontinuity from the replacement leaflet (280) to the stent-valveframe (270).

The free-edge supported replacement valve leaflets of the presentinvention are intended to be attached to an expandable stent-valve frame(270) that is used as a transcather mitral valve replacement (TMVR)device. The stent-valve has a waist frame (270) located adjacent theannulus (130), an upper bulb (820) can be attached to the waist andlocated in the LA (230), and a frustum-shaped housing (400) can beattached to the waist and located downsteam from the waist in the LV(240) as shown in FIG. 15B. A covering (740) material formed from a thinpolymeric or tissue matrix film or a thin woven fabric can be attachedto the upper bulb (820), the waist (300), and other portions of thestent-valve frame (270) to ensure that blood is not allowed to pass fromthe LV (240) to the LA (230) when the replacement leaflets (280) are ina closed configuration (608) as is found during systole for a mitralvalve.

The stent-valve frame (270) containing the free-edge supported leafletsof the present invention can be a single member stent-valve (830)wherein the stent-valve frame (270) that contains the replacementleaflets (280) is attached directly to the native mitral valve tissues.The stent-valve frame can be attached to the mitral valve tissues usingany attachment method or design that is currently being used oranticipated for use in attaching a stent-valve frame (270) to the mitralannulus, mitral leaflets, heart myocardium, or other native tissues ofthe heart for TAVR or TMVR procedures.

The waist of one embodiment of the present stent-valve frame can beattached to the annulus (130) via a series of 16 barbs (840) (range8-20) located along the perimeter (620) of the waist or other region ofthe stent-valve frame (270) as shown in FIGS. 16A-16B; the barbs (840)are comprised of barb struts (850) and barb tips (860). An upper bulb(820) can be attached to the upstream end (415) of the waist to assistwith positioning the stent-valve frame (270) adjacent the native mitralvalve tissues and to assist with forming a seal with the mitral annulusand the LA (230) tissues. A covering (740) can be placed and attached toportions of the stent-valve frame (270), including, for example, theupper bulb (820), the waist (300), and portions of the frustum-shapedhousing (400). Since the free-edge supported replacement leaflets (280)have a linear attachment to the stent-valve frame in a circular path,the covering (740) does not need to extend on any region of thestent-valve frame (270) downstream (330) of the replacement leafletlinear attachment (630) which attaches the replacement leaflet base(550) to the stent-valve frame (270). The covering (740) ensures thatblood is unable to traverse from the LV (240) to the LA without passingdirectly across the free edge supported replacement leaflets (280) fromthe LV (240) to the LA (230) in an upstream direction (865) with theleaflets in a closed configuration (608). The covering (740) alsoassists in reducing leakage around the outside (920) of the stent-valveframe between the stent-valve frame (270) and the native valve annulus(130) or other native valve tissues of the heart. The barbs (840) can beballoon expandable (BE) barbs (840) that are in an inactiveconfiguration located toward the inside (870) of the stent-valve frameduring delivery of the stent-valve (275) in a small diameterconfiguration (1120) contained within a delivery sheath (1130) as shownin FIG. 16E and during expansion of the stent-valve frame (270) to alarger diameter configuration (1140) that is in contact along itsperimeter with the native tissues of the heart valve as shown in FIG.16A. The waist contains a backing element (880) or backing member (880)such as a backing fiber (890) that is attached to the stent-valve frameand forms a fixed member against which an outward force (900) can beapplied by an expanding torus balloon (910) to push the barbs (840)outwards thereby activating the barbs (840) to place the barb tips (860)into a location outside (920) of the stent-valve frame (270) as shown inFIG. 16B; the activated barbs (840) are then able to extend into nativemitral valve tissues and prevent the stent-valve frame from migration toa position either upstream (865) or downstream (330). A torus balloon islocated on the outside (920) of the backing element and on the inside(870) of a barb strut (850). After the stent-valve has been deliveredsuch that the waist frame (270) has been expanded to an expandedconfiguration (1140) located adjacent to the annulus (130), the torusballoon is inflated to cause the barb struts (850) to extend outwardsand drive the barb tips (860) to the outside (920) of the stent-valveframe (270) and into the annulus (130) as shown in FIG. 16B. The torusballoon can be implanted along with the stent-valve of the presentinvention; the saline, saline-based, or blood compatible inflationmedium used to inflate the balloon can be allowed to leak out of theballoon inflation port over time. Further detailed description of thisand other embodiments and methods of use for the torus balloon aredescribed in earlier embodiment of the present patent application and inpatent applications that are referenced herein and incorporated fullyinto the present patent application by reference.

Another method for attaching the stent-valve frame (270) of a singlemember stent-valve (830) containing free-edge supported leaflets of thepresent invention to the native heart tissue is shown in FIG. 16C. Inthis embodiment a plurality of holding arms (930) are attached to thestent-valve frame (270) and extend distally (940) on the luminal side(950) of the native mitral valve leaflet (100), extend around thefree-edges (150) of the native mitral valve leaflets and through thecordae tendineae (170), and extend on the LV wall side (960) of thenative leaflets (100) to a junction (970) of the native leaflets (100)with the mitral annulus (130) on the back side (965) of the nativeleaflets (100). The holding arms (930) extend to the junction of thenative leaflets (110) with the mitral annulus (130) to prevent migrationof the stent-valve frame (270) from the LV (240) to the LA (230) andreduce other potential movement of the stent-valve. The stent-valveframe (270) can have supports (340) attached to the waist (300) or tothe frustum (400); the supports (340) having a distal end (490) thatcontains the fastening sites (350) to which one end of each of the cords(500) can be attached; the other end of each of the cords (500) willtherein further attach to the replacement leaflet free edges (540) ofthe free-edge supported leaflets (280) of the present invention. Thereplacement leaflet base (550) is attached via a liner attachment (630)to the stent-valve frame (270). As shown in this embodiment the linearattachment (630) of the replacement leaflets (280) to the stent-valveframe (270) occurs at the junction of the waist inlet (415) to the upperbulb (820); this location for the linear attachment (630) allows thereplacement leaflets (280) to have a longer leaflet length (i.e., longerthan a linear attachment (630) to the frame located further distally(940)) without interfering with native mitral valve structures includingthe cordae tendineae and the native mitral valve leaflets. Otherembodiments of the present invention can also have the linear attachment(630) located upstream on the stent-valve frame near the upper bulb in amanner similar to that shown for this embodiment.

In another embodiment for a single member stent-valve (830), thestent-valve frame (270) of the present invention can be attached to themyocardial wall (980) near the LV apex (990) via a tether (1000) to holdthe stent-valve frame (270) from migration from the LV (240) to the LA(230) as shown in FIG. 16D. Such a tether can be attached to a lateralsupport member (560) that joins between two fastening sites (350), forexample. The tether extends through the myocardium and is attached via abutton (1010) that slides and locks along the tether to provide thetether with adjustable tension (1015) from the stent-valve frame (270)to the myocardium of the heart (980).

The stent-valve frame (270) for the free-edge supported leaflets (280)of the present invention can also be used as a valve member (1020) orsecond component (1020) of a dual member stent-valve (1030) as shown inFIGS. 17A and 17B. As shown in FIG. 17A a first component (1040) orsupport member (1040) can be placed across the mitral valve annulus(130) and attached to the mitral annulus or other native mitral valvetissues via barbs (840) that are located along a perimeter (320) of thestent-valve frame (270) of the first component (1040) or support member(1040) (which does not contain the replacement leaflets). The firstcomponent (1040) or support member (1040) is delivered in an unexpandedconfiguration and is expanded outwards into contact with the mitralannulus (130) prior to activation of the barbs (840). Once the supportmember is located adjacent the mitral annulus, the torus balloon (910)is inflated to activate the barbs (840) to the outside (920) of thestent-valve frame (270) of the support member (1040) and into the nativetissues of the mitral valve. The stent-valve frame (270) of the presentinvention is then placed as a valve member (1020) or second component(1020) into the open central lumen (1050) of the first component (1040)and allowed to expand into contact with the first component (1040). Thesecond component (1020) can have a waist having a concave secondcomponent region (1060) or other geometrical shape that locks or fitsgeometrically with a concave first component region (1070) to preventmigration of the stent-valve frame (270) of the second component (1020)from migrating relative to the first component (1040). The stent-valveframe (270) of the second component (1020) contains the supports (340)and fastening sites (350) that are attached to cords (500) which in turnare attached at their opposite end to the replacement leaflet free edges(540) of the free-edge supported replacement leaflets (280) to preventthe replacement leaflets (280) from everting. The replacement leaflets(280) are also attached along the leaflet base (550) to the stent-valveframe (270) following a linear attachment (630) along the perimeter(320) of the stent-valve frame (270).

Another embodiment for a dual member stent-valve (1030) that uses thestent-valve frame and free-edge supported leaflets as a valve member(1020) or second component (1020) is shown in FIG. 17B. In thisembodiment the first component (1040) or support member (1040) is astent frame that does not contain the replacement leaflets (280); thefirst component stent frame (1045) is delivered to a location adjacentto the mitral valve tissues. A plurality of holding arms (930) areattached to the first component stent frame (1045); the holding armsextend distally (940) on the luminal side (950) of the native leaflets,around the free-edges (150) of the native leaflets (100), and proximallyon the LV wall side (960) of the native leaflets (100) to a junction(970) of the native leaflets (100) with the annulus (130) or myocardialLV (240) wall. The plurality of holding arms (930) prevents migration ofthe first component (1040). The first component (1040) serves as asupport member that allows a second component (1020) to be deliveredwithin its open central lumen (1050) and provide a means for attachmentof the second component (1020) to the first component (1040). Otherembodiments for the BE barb are described in more detail in other patentapplications that are referenced and are fully incorporated herein byreference.

The first component (1040) can have a geometric feature such as aconcave first component region (1070) that extends along the waist orother portion of the stent-valve frame (270) of the first component(1040). The first component (1040) also resists further diametricexpansion thereby providing an outer member or outer diameter limitingelement (1075) (i.e., a flexible but non-stretchable fiber that extendsaround the perimeter of the first component frame (1045) that provides amaximum expansion diameter for the first component frame (1045)) intowhich a second component (1020) can be expanded under a large outwardforce (900) that will resist migration of the second component (1020)relative to the first component (1040) due to friction and geometricallocking between the first component (1040) and second component (1020).The second component (1020) or valve member (1020) can have thestent-valve frame (270) and free-edge supported replacement leaflets(280) of the present invention. The stent-valve frame (270) containssupports (340) that have fastening sites (350) located at the distal end(490); the fastening sites (350) attach to cords (500) that are thenattached to free edges (540) of the free-edge supported replacementleaflets (280). The second component is then expanded within the opencentral lumen (1050) of the first component (1040). The second component(1020) can have a waist (300) of the second component stent-valve frame(270) that has a geometrical feature such as a concave second componentregion (1060) that will lock into the geometrical feature of the firstcomponent (1040) to prevent migration of the second component (1020).The stent-valve frame (270) can be a BE or SE stent-valve framestructure; it can be expanded outwards to generate a friction betweenthe second component (1020) and the first component (1040) to preventmigration of the second component (1020).

The barbs (840) that are located along the perimeter of the firstcomponent (1040) of a dual member stent-valve (1030) can alternately beSE barbs (840) that have a normal equilibrium configuration with thebarbs (840) extending outwards. The first component frame (1045) has abacking elements (880) such as a plurality of stent arms (1080) attachedto the first component frame (1045) and extending to the inside of thefirst component frame (1045) adjacent to the barbs (840) of the firstcomponent frame (1045) as shown in FIGS. 18A and 18B. During delivery tothe site of the mitral valve the first component frame (1045) iscontained within an external sheath and the barbs (840) are held in aretracted configuration by a control fiber (1090) that interfaces withthe backing element (880) to hold the barb strut (850) inwards in aninactive configuration as shown in FIG. 18A. After the first componentframe (1045) has been located adjacent the mitral annulus (130), thecontrol fiber (1090) is released by providing tension and therebyreleasing the barb strut to move outwards and causing the barb tip (860)to be located outside (920) of the first component frame (1045) and intothe tissue of the annulus (130) as shown in FIG. 18B. This activation ofthe barb tip (860) prevents the first component frame (1045) frommigrating upstream (865) or downstream (330). Following activation ofthe barbs (840) the second component (1020) containing the free-edgesupported replacement leaflets (280) of the present invention is placedinto the open central lumen (1050) of the first component (1040) asshown in FIG. 18B. The second component (1020) is located such that thesecond component waist (1110) is located adjacent the first componentframe (1045). Such location of the second component (1020) can beattained by the presence of and upper bulb (820) that is located in theLA (230) and upstream (865) of the first component frame (1045). Also,concave geometry can be located in the first component frame (1045) andin the second component waist (1110) as described in other embodiments;such concave shapes or other geometrical shapes will self-locate thesecond component (1020) relative to the first component (1040) and lockthe two components together such that the second component (1020) cannotmigrate toward the LA (230) or the LV (240). The second component ofthis embodiment can have the same structure for the stent-valve frame(270) and replacement leaflets (280) as described in earlier embodimentsas shown in FIG. 18B. Other embodiments for the SE barb are described inmore detail in other patent applications that are referenced and arefully incorporated herein by reference.

It is further understood that the present invention for free-edgesupported leaflets for a TMVR device can utilize other means forattaching the frame of the stent-valve to the native mitral tissueapparatus to prevent migration of the stent-valve; such attachment meanscan involve attachment to the LA (230), the mitral annulus, the mitralleaflets, the cordae tendineae, the papillary muscles, the junction ofthe mitral leaflets with the myocardial wall, and the myocardial walltissue including the myocardial apex. Such approaches include clips andhooks that grab or clip the free-edges of the mitral valve, cords (500)that attach the stent-valve with the myocardial tissue near the apex,rings that surround the mitral valve leaflets adjacent the lateralmyocardial wall and within the LVOT, and attaching directly to themitral leaflet surface. The free-edge supported mitral valve leafletsprovide a lower profile for the leaflets due to the direct attachment ofcords (500) to the free edge (540) of the leaflets; this method forleaflet attachment differs from that found with semi-lunar valveattachment found with aortic valve, for example. The stresses foundwithin the valve leaflet needed to support the aortic valve fromeversion are greater than those found in the mitral valve even thoughthe mitral valve has a greater surface area and the pressure foundwithin the LV (240) are much larger than those found within the aorta.Therefore, the leaflets that are free-edge supported can be formed witha thinner profile than a semi-lunar valve that does not have any supportalong its free edge.

Reference numerals used in the specification and found on the drawingsof the various embodiments of the present invention are intended torepresent similar structures having similar functions. Also, it isunderstood that aspects of one or more embodiments can be combined withother aspect from another embodiment to form an embodiment that is alsoincluded in the present invention.

The free-edge supported leaflets of the present invention can be usedwith a variety of stent-valve frames including those embodimentspresented in the present patent application and those that areincorporated in the present patent application by reference. Other framedesigns are also anticipated for use with the free-edge supportedleaflets of the present invention including SE and BE frame designs usedfor TAVR procedures or other stent-valve applications. The use offree-edge supported leaflets is not limited to those frame designs thathave been described herein or have been referenced herein.

1. A stent-valve that is deliverable via transcather delivery to anative heart valve said stent-valve directing blood flow downstream andprevent blood flow upstream in a native heart of a body, saidstent-valve comprising; A. an expandable stent-valve frame, saidstent-valve frame expanding from a smaller diameter deliverableconfiguration to a larger diameter configuration within the native heartvalve, B. replacement leaflets having a leaflet base that is attachedvia a linear attachment to said stent-valve frame, each of said leafletshaving a leaflet free edge, said leaflet free edges forming a coaptationwith another of said leaflet free edge in a closed configuration forsaid leaflets, C. said stent-valve frame comprising fastening sitesattached thereto, said fastening sites being located downstream of saidreplacement leaflets, D. each of said fastening sites having a separatecord attached thereto; each of said cords being attached to saidfastening site by a cord first end, each of said cords further having acord second end, said cord second end being attached to said leafletfree edge, E. wherein said cord prevents said leaflet free edge fromeverting due to blood pressure in the native heart.
 2. The stent-valveof claim 1 wherein said linear attachment does not extend in the axialdirection to support said leaflet free edges from everting, said linearattachment forming a shape of a circle, an oval, or a saddle shape. 3.The stent-valve of claim 1 wherein a fastening site distance betweeneach of said fastening sites is less than a diameter of said stent-valveframe at the location of said linear attachment.
 4. The stent-valve ofclaim 1 wherein said stent-valve frame has support members attachedthereto, said support members extending downstream of said replacementleaflets to said fastening sites.
 5. The stent-valve of claim 4 whereinsaid stent-valve frame comprises a frustum-shaped frame, saidfrustum-shaped frame comprising said support members, said supportmembers being contiguous with a wall structure of said frustum-shapedframe.
 6. The stent-valve of claim 1 wherein said stent-valve framecomprises a frustum-shaped frame, said frustum-shaped frame comprisingsaid fastening sites.
 7. The stent-valve of claim 1 wherein twofastening sites are attached to said stent-valve frame.
 8. Thestent-valve of claim 1 wherein three fastening sites are attached tosaid stent-valve frame.
 9. The stent-valve of claim 1 wherein saidreplacements leaflets are comprised of two replacement leaflets.
 10. Thestent-valve of claim 9 wherein each of said two replacement leaflets areattached via said cords to the same specific one of said fasteningsites.
 11. The stent-valve of claim 1 wherein said replacement leafletsare composite replacement leaflets formed from a polymer matrix or atissue matrix with a leaflet support structure embedded within saidpolymer matrix or said tissue matrix.
 12. The stent-valve of claim 11wherein said composite replacement leaflets are formed with a leafletsupport structure comprised of axial and circumferential fibers embeddedwithin said polymer matrix or said tissue matrix.
 13. The stent-valve ofclaim 11 wherein said composite leaflets are formed with a leafletsupport structure comprised of a thin metal or a thin polymeric filmembedded within said polymer matrix or said tissue matrix.
 14. Thestent-valve of claim 1 wherein said stent-valve is a single componentstent-valve, said stent-valve frame being expanded into direct contactwith the native valve tissues and forming an attachment with the nativeheart valve tissues.
 15. The stent-valve of claim 1 wherein saidstent-valve frame contains barbs attached along a perimeter of saidstent-valve frame, said stent-valve further comprising a torus balloonattached along a perimeter of said stent-valve frame adjacent to saidbarbs, said torus balloon being inflatable to activate said barbs toextent outside of said stent-valve frame into tissue of the native heartvalve tissues.
 16. The stent-valve of claim 1 wherein said stent-valveframe contains holding arms that attach said stent-valve frame to nativevalve leaflets of the native heart valve to prevent migration of saidstent-valve upstream in the native heart of the body.
 17. Thestent-valve of claim 1 wherein said stent-valve is a second component ofa dual component assembly, said dual component assembly comprising; A. afirst component having a support frame, said support frame beingattached to the native heart valve tissue to prevent migration of saidfirst component in the native heart of the body, said first componentproviding unrestricted flow of blood between a left atrium and a leftventricle, B. said second component being expanded within an opencentral lumen of said first component, said second component having ageometrical shape or frictional fit that locks with a matchinggeometrical shape of said first component to prevent migration of saidsecond component relative to said first component.
 18. A stent-valve fortranscatheter placement within a native heart valve to direct blood flowdownstream and prevent blood flow upstream, the stent-valve comprising;A. an expandable stent frame, said stent frame having a small diameterconfiguration that is able to be delivered via standard transcathetermethods and expandable to a larger diameter configuration that islocated within the native heart valve, B. two free-edge supportedleaflets attached to said stent frame forming a linear attachment, saidlinear attachment not extending with an axial length that could supporteversion of said free-edge supported leaflets, said free edge supportedleaflets having free edges that form a coaptation of said free-edgesupported leaflets in a closed configuration, C. a first support memberand a second support member contiguous with or attached to said stentframe and extending downstream of said free edges; said first supportmember having a first fastening site at a distal end of said firstsupport member and said second support member having a second fasteningsite at a distal end of said second support member, D. said firstfastening site being attached to first end of a first cord, said secondfastening site being attached to a first end of a second cord, E. asecond end of said first cord being attached to said free edge of afirst leaflet of said free-edge supported leaflets, a second end of saidsecond cord being attached to said free edge of a second leaflet of saidfree-edge supported leaflets, F. wherein said first cord and said secondcord prevent said first leaflet and said second leaflet from evertingand thereby preventing passage of blood flow upstream.
 19. Thestent-valve of claim 18 wherein said first fastening site is separatedfrom said second fastening site by a fastening site distance that issmaller than a diameter for said stent frame in said larger diameterconfiguration.
 20. A stent-valve that is deliverable via transcatherdelivery to a native heart valve, said stent-valve directing blood flowdownstream and preventing blood flow upstream in a native heart of thebody, said stent-valve comprising; A. an expandable stent-valve frame,said stent-valve frame expanding from a smaller diameter deliverableconfiguration to a larger diameter configuration within the native heartvalve, B. replacement leaflets having a leaflet base that is attached tosaid stent-valve frame, each of said leaflets having a leaflet freeedge, said leaflet free edge forming a coaptation with another of saidleaflet free edge in a closed configuration for said leaflets, C. saidstent-valve frame comprising fastening sites attached thereto, saidfastening sites being located downstream of said leaflet free edges, D.each of said fastening sites having a separate cord attached thereto;each of said cords being attached to said fastening site by a cord firstend, each of said cords further having a cord second end, said cordsecond end being attached to said leaflet free edge, E. wherein saidseparate cords prevents said leaflet free edges from everting due toblood pressure in the native heart.